For effective safe storage and use of parenteral fluids and similar sterile solutions, it is necessary that such fluids be stored in sterile, tamper-proof containers provided with means to facilitate withdrawal of the fluid without a substantial sacrifice of sterility. Some containers or bags are formed of flexible plastic in such a manner as to enclose parenteral fluid or other sterile fluid. The container is later entered through a sealed port structure or the like in order to dispense measured amounts of the contents therefrom. As the liquid contents from such flexible sealed plastic containers are dispensed, the container collapses, and therefore no venting of the container with air which might carry contaminants is required. In some previously known constructions, the sealed bag containers have been provided with entry or exit ports through which an entry spike or needle could be inserted and retained in tight sealed relationship therewith, the port frequently consisting of a tubular needle supporting structure secured at one end or in some cases on a wall of the bag by a flange or similar structural element. In some constructions, the portion of the bag enclosed by the tubular element served as a pierceable diaphragm. A resilient plug would then be fitted into the tubular element to hold the needle inserted through the plug in the side of the bag.
Recently, interest has developed in the use of blow molded flexible containers as containers for sterile solutions. Such containers may be blow-molded to provide a neck end which is sealed, and before the sealing of the neck end, sterile solution may be introduced into the container.
In one such container as shown in U.S. Pat. No. 3,746,001, a tubular gripping sleeve of semi-rigid plastic is positioned about the closed end of the tubular neck so as to provide an internal pierceable diaphragm. The inside diameter of the sleeve which extends beyond the tubular neck is the same as the inside diameter of the tubular neck and is of a size which will provide sealing engagement of an entry spike fitted into the sleeve. The end of the sleeve is either capped by a plug or by a removable tab or cover for maintaining sterility prior to use. However, there is no guarantee of sterility with such covers since they can be removed and reinstalled without an indication of their having been tampered with. Another drawback to such a closure system is that the entry spike is difficult to slide through the plastic sleeve and tubular neck unless it has been lubricated.
Another pierceable access port assembly for a flexible sterile solution container adapted for easy securement to the container is shown in co-pending application Ser. No. 443,011, filed Feb. 15, 1974, and titled Pierceable Access Port Assembly, and assigned to a common assignee herewith. The present invention constitutes an improvement in simplicity of construction and use over those shown in previous known constructions.